US healthcare reforms backed by Barack Obama passed a vital vote in the Senate , clearing the way for a bill to be passed before Christmas.

In the early hours a procedural measure to block Republican delaying tactics was passed in a 60-40 vote, with unanimous Democrat backing.

The vote all but assures the passage of healthcare reforms through the Senate, a feat that eluded generations of Democrats.

"We'll get this passed before Christmas and it will be one of the best Christmas presents this Congress has ever given the American people," Democratic senator Tom Harkin said.

The bill will provide 30 million uninsured Americans with health cover.

According to reports, the atmosphere was partisan as senators cast their votes from their desks, a practice reserved for issues of particular importance.

White House officials who have worked closely on the issue watched from the visitor's gallery, along with Vicki Kennedy, the widow of Democratic senator Ted Kennedy, who championed healthcare across a Senate career that spanned more than 40 years.

Republicans conceded that they could no longer block the bill, after the vote passed in a snowbound Washington.

"The impact of this vote will long outlive this one frantic, snowy weekend in Washington," Republican Senate leader, Mitch McConnell, said. "This legislation will reshape our nation, and Americans have already issued their verdict – they don't want it."

In a TV address from the White House before the vote, Barack Obama said: "After nearly a century-long struggle, we are on the cusp of making healthcare reform a reality in the United States of America."

But the passage of the bill will not have been ensured without painful compromises that have dismayed leftwing Democrats.

The Democratic leadership of the Senate was held to ransom by individual senators as every one of the 60 members who take the Democratic whip had to back the bill to avoid a Republican blocking tactic, the so-called "filibuster".

Harry Reid, the Democratic leader in the Senate, had already bowed to the will of the independent senator Joe Lieberman and dropped the public option – a government-run health insurance scheme – that was seen as crucial by liberal Democrats as a means of reigning in the all-powerful private health insurers.

In 13 hours of dramatic talks on Friday, the Democratic leadership was forced to accept further whittling down of the bill at the hands of Ben Nelson, an outspoken anti-abortionist. Provoking a storm of protest from pro-abortion groups, Reid placated Nelson by introducing an amendment that would ensure no federal money was spent subsidising abortions.

A similar clause was included in the reforms that pass through the House of Representatives. In the Senate model, anyone taking insurance through the exchanges set up under the bill that would provide cheap government-subsidised packages for people who cannot get insurance through work, can take up coverage that includes abortion, but they must pay for the abortion element separately.

Pro-abortion groups were livid. Cecile Richards, of the Planned Parenthood Federation of America, said: "It is a sad day when women's health is traded away for one vote. [We] do not think that healthcare reform is the forum to litigate abortion policy."

Naral Pro-Choice America, one of the country's largest abortion rights groups, said the compromise would place an unacceptable administrative burden on women buying abortion coverage. "This situation is a reminder that, despite our significant pro-choice gains in the last two election cycles, anti-choice lawmakers still outnumber our allies."

David Axelrod, Obama's senior adviser, defended the compromise bill during television interviews, saying it "preserved the rights of women to choose, and doesn't change existing law one way or another".

• This article was amended on Tuesday 22 December 2009. The original referred to Senator Bob Nelson. This has been corrected.